Chakotay falls for a woman whom he can't remember.
Kellin, a Ramuran, comes aboard Voyager seeking asylum and tells Chakotay that she spent weeks on the ship before and that the two fell in love. Her people cannot be remembered by others or retained by technology for more than a few hours, so neither Chakotay nor the ship's records hold any trace of her earlier visit.
As they work together against a Ramuran tracker sent to bring her home, Chakotay falls for her again. The tracker then wipes Kellin's own memories of Voyager, and she no longer shares his feelings. She leaves with him, and Chakotay writes down what happened on paper so that some record of her survives.